Furthermore, the physical size of nuclear bombs was drastically reduced, permitting the development of battlefield nuclear weapons, such as nuclear artillery shells and small missiles that can be fired from portable launchers in the field. This allowed strategists to consider the possibility of waging a limited nuclear war.

After the war, the US Atomic Energy Commission became responsible for the supervision of all nuclear matters in the United States, including weapons research. Although nuclear bombs were originally developed as strategic weapons to be carried by large bombers, such as the B-29 and B-52, from the 1950s nuclear weapons were produced for both strategic and tactical applications. Not only can they be delivered by different types of military aircraft, but rockets and guided missiles of many sizes were built to carry nuclear warheads, to be launched from the ground, the air, or under the sea. Intercontinental ballistic missiles are large rockets capable of carrying multiple warheads for delivery to separate targets thousands of kilometres from launch.

Research in nuclear weapons continues in the United States at Los Alamos; at Lawrence Livermore Laboratory, California; in Britain, at Aldermaston; and in Russia, France, and China. Reduction in superpower nuclear forces, as a result of treaties such as the Strategic Arms Reduction Treaties (START) I and II, has produced a need for labs to apply research to the decommissioning and refitting of weapons.